Commitments, Contingencies and Guarantees - Credit Exposure from Loan Commitments (Detail) (USD $) In Millions, unless otherwise specified	Nov. 30, 2013
Commitments And Guarantee Obligations [Line Items]
0 - 12 Months	$ 35.6
1 - 5 Years	748.2
Greater Than 5 Years
Total Corporate Lending Exposure	783.8
Corporate Lending Exposure at Fair Value	316.2
Corporate Lending Commitments	467.6
Non-investment grade [Member]
Commitments And Guarantee Obligations [Line Items]
0 - 12 Months
1 - 5 Years	79.1
Greater Than 5 Years
Total Corporate Lending Exposure	79.1
Corporate Lending Exposure at Fair Value	9.5
Corporate Lending Commitments	69.6
Unrated [Member]
Commitments And Guarantee Obligations [Line Items]
0 - 12 Months	35.6
1 - 5 Years	669.1
Greater Than 5 Years
Total Corporate Lending Exposure	704.7
Corporate Lending Exposure at Fair Value	306.7
Corporate Lending Commitments	$ 398.0